Question 1

Which one of the following sets of laboratory values correctly reflects an iron deficiency state?&#10;A) Transferrin saturation high,serum iron decreased,TIBC high&#10;B) Transferrin saturation high,serum iron increased,TIBC high to normal&#10;C) Transferrin saturation low,serum iron decreased,TIBC low to normal&#10;D) Transferrin saturation low,serum iron increased,TIBC normal

Accepted Answer

Transferrin saturation is low because there is insufficient iron to bind to transferrin. Serum iron is decreased because there is not enough available iron in the bloodstream. TIBC is low to normal because the body is attempting to conserve iron by decreasing the amount of transferrin available to bind with iron.

Question 2

A patient presents with yellowish skin and eyes,fatigue,and mild motor system dysfunction.Upon assessment in the laboratory,the total bilirubin concentration was shown to be 3.0 mg/dL (normal 0.2-1.0 mg/dL)with negative urinary bilirubin.Liver function tests are normal.The most likely diagnosis in this case would be:

A) Crigler-Najjar syndrome type II.
B) Lucey-Driscoll syndrome.
C) hemolytic anemia.
D) Gilbert syndrome.

Gilbert syndrome.

Accepted Answer

The patient shows symptoms of jaundice, fatigue, and mild motor system dysfunction, which are all consistent with Gilbert syndrome. Total bilirubin concentration is elevated, but there is no evidence of urinary bilirubin or abnormal liver function tests. Gilbert syndrome is caused by a mutation in the UGT1A1 gene, leading to impaired bilirubin metabolism and increased serum unconjugated bilirubin levels. Crigler-Najjar syndrome type II and Lucey-Driscoll syndrome also present with elevated bilirubin, but these conditions have different underlying mechanisms and additional clinical features. Hemolytic anemia can also cause hyperbilirubinemia, but it typically results in elevated levels of both unconjugated and conjugated bilirubin, as well as abnormal liver function tests.

Question 3

The most common cause of iron deficiency anemia in children is:&#10;A) bleeding ulcers.&#10;B) hemolytic anemias.&#10;C) dietary deficiency.&#10;D) megaloblastic anemia.

Accepted Answer

Iron deficiency anemia in children is most commonly caused by not getting enough iron in their diet. This can happen if a child is not eating enough iron-rich foods or if their body is not absorbing iron properly. Bleeding ulcers and hemolytic anemias are possible causes of anemia but are less common in children. Megaloblastic anemia is caused by a deficiency in vitamin B12 or folic acid and is not related to iron deficiency anemia.

Question 4

Which one of the following statements concerning TIBC is not correct?&#10;A) TIBC is decreased in chronic inflammatory disorders.&#10;B) TIBC is proportional to the amount of transferrin present.&#10;C) TIBC is decreased in an iron deficiency anemia.&#10;D) Transferrin saturation = (serum iron/TIBC) * 100.

Accepted Answer

TIBC (Total Iron Binding Capacity) is actually increased in iron deficiency anemia, not decreased. This is because the body produces more transferrin to try to capture more iron when iron levels are low.

Question 5

Regarding the individual using progesterone-based oral contraceptives,would the transferrin saturation be increased,decreased,or not affected?&#10;A) Increased&#10;B) Decreased&#10;C) Not affected

Accepted Answer

The answer of Regarding the individual using progesterone-based oral contraceptives,would...

Question 6

Iron is transported as ferric iron through the plasma by means of: A) transferrin. B) alpha₁-fetoprotein. C) ferritin. D) albumin.

Accepted Answer

Iron is transported through the plasma bound to transferrin, a protein that binds iron tightly and specifically. Transferrin has two iron-binding sites and is capable of binding up to two Fe3+ ions. Once inside the cell, the iron is released from transferrin and reduced to the ferrous form for incorporation into heme or storage in ferritin.

Question 7

What is the percent transferrin saturation given the following data: serum iron 150 $\mu$g/dL,TIBC 350 $\mu$g/dL,transferrin 300 mg/dL,and ferritin 65 ng/mL?&#10;A) 43%&#10;B) 55%&#10;C) 233%&#10;D) 500%

Accepted Answer

The percent transferrin saturation is calculated using the formula: (Serum Iron / TIBC) * 100. Given the serum iron is 150 µg/dL and TIBC is 350 µg/dL, the calculation is (150 / 350) * 100 = 42.86%, which rounds to 43%.

Question 8

In an individual using progesterone-based oral contraceptives,serum iron _____ and TIBC _____.&#10;A) increases; decreases&#10;B) is normal; increases&#10;C) decreases; decreases&#10;D) increases; increases

Accepted Answer

The answer of In an individual using progesterone-based oral contraceptives,serum...

Question 9

The inherited disorders caused by an underproduction of certain globin chains are referred to as the:&#10;A) hemoglobinopathies.&#10;B) iron deficiency disorders.&#10;C) hemoglobin variant disorders.&#10;D) thalassemias.

Accepted Answer

Thalassemias are inherited disorders caused by an underproduction of certain globin chains, which leads to a deficiency of hemoglobin. Hemoglobinopathies and hemoglobin variant disorders also refer to disorders of hemoglobin, but they are not specific to underproduction of globin chains. Iron deficiency disorders do not directly involve hemoglobin production.

Question 10

What is the mutational basis of an "elongation hemoglobin?" A) A gene deletion of the entire alpha₂ globin gene B) A reciprocal chromosomal translocation between chromosomes 16 and 14 of the alpha and beta globin chain genes C) Many fixed mutations occurring along the genes encoding for alpha₂ globin D) A single base pair mutation or frameshift at either the 3' end of exon 3 or the 5' end of exon 1 of the alpha₂ or beta globin chain

Accepted Answer

An elongation hemoglobin is a type of hemoglobin with a longer amino acid chain than normal hemoglobin. This is caused by a mutation in either the alpha or beta globin chain gene, where a single base pair mutation or frameshift occurs at the 3' end of exon 3 or the 5' end of exon 1. This leads to the addition of extra amino acids, resulting in the elongation of the hemoglobin chain. Therefore, choice D is the correct answer.

Question 11

In blood,bilirubin is unconjugated but is bound to _____ as it is transported to the liver.&#10;A) hemoglobin&#10;B) albumin&#10;C) bilirubin-transporting protein&#10;D) urobilinogen

Accepted Answer

The answer of In blood,bilirubin is unconjugated but is bound...

Question 12

High levels of unconjugated bilirubin that accumulate in the brain are called:&#10;A) hyperbilirubinemia.&#10;B) Crigler-Najjar syndrome.&#10;C) hemolysis.&#10;D) kernicterus.

Accepted Answer

The answer of High levels of unconjugated bilirubin that accumulate...

Question 13

In the initial step of the diazo reaction for direct bilirubin determination:&#10;A) the absorption of light by bilirubin near 460 nm is measured.&#10;B) bilirubin fractions are oxidized to biliverdin,which is further oxidized to purple.&#10;C) serum is added to an aqueous solution of caffeine,sodium acetate,and sodium benzoate.&#10;D) large quantities of ascorbic acid worsen the detection limit.

Accepted Answer

The answer of In the initial step of the diazo...

Question 14

An 80-year-old patient visits his physician with an elevated serum iron value and a decreased TIBC.The most likely diagnosis in this case is:&#10;A) iron deficiency anemia.&#10;B) chronic inflammation.&#10;C) hemochromatosis.&#10;D) acute bleeding ulcer.

Accepted Answer

The answer of An 80-year-old patient visits his physician with...

Question 15

Which one of the following is formed by the reduction of unconjugated bilirubin in the intestines,is found in urine,and is further oxidized to form urobilin?&#10;A) Hemoglobin&#10;B) Conjugated bilirubin&#10;C) Iron&#10;D) Urobilinogen

Accepted Answer

The answer of Which one of the following is formed...

Question 16

Regarding serum iron analysis,the maximum concentration of iron that transferrin can bind is reflected in what laboratory measurement?&#10;A) Transferrin saturation&#10;B) Hemoglobin&#10;C) Serum iron&#10;D) Total iron binding capacity (TIBC)

Accepted Answer

The answer of Regarding serum iron analysis,the maximum concentration of...

Question 17

The most popular assay used to determine iron deficiency anemia is ferritin.What are the ferritin levels in the correctly identified diagnosis in the preceding question compared to normal?&#10;A) Increased&#10;B) Decreased&#10;C) Unaffected

Accepted Answer

The answer of The most popular assay used to determine...

Question 18

The major substance formed from the breakdown of hemoglobin when senescent red blood cells are phagocytized by the reticuloendothelial system is:&#10;A) myoglobin.&#10;B) bilirubin.&#10;C) urobilinogen.&#10;D) urobilin.

Accepted Answer

The answer of The major substance formed from the breakdown...

Question 19

What soluble iron-protein complex is the form in which iron is stored in tissues?&#10;A) Ferritin&#10;B) Transferrin&#10;C) Hemosiderin&#10;D) Hemoglobin

Accepted Answer

The answer of What soluble iron-protein complex is the form...

Question 20

Bilirubin is considered to be the breakdown product of:&#10;A) cholesterol.&#10;B) protoporphyrin IX.&#10;C) glucose and maltose.&#10;D) urobilinogen.

Accepted Answer

The answer of Bilirubin is considered to be the breakdown...

Question 21

In hemoglobin F,which globin chains are different from adult hemoglobin chains and what replaces them in the adult?&#10;A) Gamma chains are replaced by betas.&#10;B) Delta chains are replaced by alphas.&#10;C) Gamma chains are replaced by alphas.&#10;D) Delta chains are replaced by betas.

Accepted Answer

The answer of In hemoglobin F,which globin chains are different...

Question 22

Increased total iron in serum is common in all of the following except:&#10;A) iron intoxication.&#10;B) hemosiderosis.&#10;C) chronic inflammation.&#10;D) sideroblastic anemia.

Accepted Answer

The answer of Increased total iron in serum is common...

Question 23

The two pairs of globin chains in normal HbA hemoglobin are:&#10;A) alpha and gamma.&#10;B) beta and gamma.&#10;C) alpha and beta.&#10;D) beta and delta.

Accepted Answer

The answer of The two pairs of globin chains in...

Question 24

The oxidation of the Fe⁺² of hemoglobin to the Fe⁺³ of methemoglobin by ferricyanide is the initial step in the: A) Mentzer index reaction for screening of $\alpha$-thalassemia. B) cyanmethemoglobin method of hemoglobin determination. C) Ehrlich reaction for the determination of bilirubin. D) HPLC methods for separating hemoglobin fractions.

Accepted Answer

The answer of The oxidation of the Fe⁺² of hemoglobin...

Question 25

In a certain hemoglobin structural variant,a deletion in the coding gene results in a reduction of the production of the beta globin chain.This will result in:&#10;A) decreased quantity of HbA.&#10;B) hemolysis of red blood cells due to unstable hemoglobin.&#10;C) a sickling disorder due to insoluble hemoglobin.&#10;D) an $\alpha$-thalassemia due to overproduction of alpha-globin chains.

Accepted Answer

The answer of In a certain hemoglobin structural variant,a deletion...

Deck 28: Hemoglobin, Iron, and Bilirubin